My E85 3.0 SE has been in the garage Sorn'd since November ( with Ctek ) - every week or so I start it up and run it for about 10 mins - today as usual I started it up - coolant light came on - turned engine off ,restarted and light went off - so checked level and added about 1/2 pint - bearing in mind I've never checked it in the 2 years I've had it I wasn't that bothered until I noticed a small amount of water on the sump tray - I've soaked it up with some kitchen towel , ran the car for around 10 minutes - no more water evident and coolant level remains full - I say water because that's what it looks like and has no smell like you would expect from coolant - checked headlight washer tank - practically full - no evidence of cracking in expansion bottle . Is it possible that by running it for a while causes water to get pushed out of the expansion tank or am I talking rubbish - any other ideas ?
mystery water leak
- Thread starter gov
- Start date
gov said:
Yes, I'm afraid that is rubbish.
Two things. You're doing this all wrong if the car is laid up for a few months. Starting it up like that is worthless and doing more harm than good. Just keep the battery charged up using a trickle charger, and if you want to run the car do it for a lot longer, get it up to operating temperature properly. You can use the hidden menu on the speedo or diagnostics to check the temp.
Secondly, I don't know what water you are finding, but it could be coming from the air con if that is running. But if it is connected to the coolant light coming on, then it's likely you have a small leak that has just built up over a few months. This is not in itself a big deal, but you should try and find it and you'll be more likely to do so if the engine is fully warmed up.
Coolant can leak any time, whether the engine is running or not.
Had a more detailed look this morning - seems to be leaking slightly from top hose - the one nearest the top on the left looking down - its the thick hose that goes from the engine mount back through the radiator - only leaks when engine is running ( only ran it for 2 mins to check ! ) there's what looks like a circlip around it and the coolant/water is seeping through slowly at the opening of the pipe - if I'm lucky it might just need tightening otherwise it will need a new hose - a bugger to get to as always 
Worth trying myself ?
Worth trying myself ?Do you mean nr1 in this pic
http://bmwfans.info/parts-catalog/E85/Europe/Z4_2.5i-M54/R-N/feb2004/browse/radiator/cooling_system_water_hoses/
If so, check temp sensor nr5. Release electric connector, then you can pull temp sensor out. Temp sensor has green O ring, which is (I think) quite common fail.
You can buy o ring separately, but the whole temp sensor is quite cheap.
http://bmwfans.info/parts-catalog/E85/Europe/Z4_2.5i-M54/R-N/feb2004/browse/radiator/cooling_system_water_hoses/
If so, check temp sensor nr5. Release electric connector, then you can pull temp sensor out. Temp sensor has green O ring, which is (I think) quite common fail.
You can buy o ring separately, but the whole temp sensor is quite cheap.
jaq03 said:
Yes I think it is no 1 pipe - the water/coolant is seeping out of the end of the pipe where it connects to the engine block - as I said it may just need tightening but it doesn't look like a circlip ( from what I can see ) - I don't think it's the sensor O ring.
Just had another look and you could be right - the water is coming out directly underneath the sensor - if I pull it out will coolant come gushing out ?
Coolant dribbles out slowly, dont worry. You have time to take it out and check it. You'll see very quickly if it's damaged or not.
When I replaced it I stuffed the hole with thin plastic bag and replaced seal
Part number for O ring is 13.62.1.743.299 and paid 2,5€ at stealers.
http://www.bimmerfest.com/forums/showthread.php?t=409007
When I replaced it I stuffed the hole with thin plastic bag and replaced seal
Part number for O ring is 13.62.1.743.299 and paid 2,5€ at stealers.
http://www.bimmerfest.com/forums/showthread.php?t=409007